Abstract

The subjective nature of self-reported dietary intake assessment methods presents
numerous challenges to obtaining accurate dietary intake and nutritional status. This
limitation can be overcome by the use of dietary biomarkers, which are able to objectively
assess dietary consumption (or exposure) without the bias of self-reported dietary
intake errors. The need for dietary biomarkers was addressed by the Institute of Medicine,
who recognized the lack of nutritional biomarkers as a knowledge gap requiring future
research. The purpose of this article is to review existing literature on currently
available dietary biomarkers, including novel biomarkers of specific foods and dietary
components, and assess the validity, reliability and sensitivity of the markers. This
review revealed several biomarkers in need of additional validation research; research
is also needed to produce sensitive, specific, cost-effective and noninvasive dietary
biomarkers. The emerging field of metabolomics may help to advance the development
of food/nutrient biomarkers, yet advances in food metabolome databases are needed.
The availability of biomarkers that estimate intake of specific foods and dietary
components could greatly enhance nutritional research targeting compliance to national
recommendations as well as direct associations with disease outcomes. More research
is necessary to refine existing biomarkers by accounting for confounding factors,
to establish new indicators of specific food intake, and to develop techniques that
are cost-effective, noninvasive, rapid and accurate measures of nutritional status.